russians earlier told secretary of state kerry they would not invade ukraine and said this troop movement was allowed in a treaty they previously had with ukraine but president obama came to the white house briefing room to urge putin to stop. >> any violation of ukraine's sovereigncy and territorial integrity would be deeply destabilizing which is not in tint of ukraine, russia or europe. it would represent a profound interference in matters that must be determined by the ukrainian people. >>> most here agree there's little the u.s. can do or some say even should do since we need putin's cooperation on issues more critical to the u.s. than ukraine like iran and syria and north korea and guessing by some here putin will not send masses of troops into the central part of ukraine. world will be watching, larry, to see if russian troops in the crimea act like invaders or peacekeepers. back to you. >> putin has double crossed us in most of those place us mentioned particularly syria and iran to a lesser extent but still north korea. i want to know, you mentioned this, first time i heard about